If you want to know where the 97%-figure comes from...

http://iopscience.iop.org/1748-9326/8/2/024024

John Cook et al
"Quantifying the consensus on anthropogenic global warming in the scientific literature"
Environ. Res. Lett. 8 024024, 2013
http://dx.doi.org/10.1088/1748-9326/8/2/024024

Excerpt from Abstract:
"We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11?944 climate abstracts from 1991–2011 matching the topics 'global climate change' or 'global warming'. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming."